Propulsion system for small boats



y 3, 1965 J. R. MATTSON ETAL 3,194,205

PROPULSION SYSTEM FOR SMALL BOATS 5 Sheets-Sheet 1 Filed Jan. 51, 1963F/ 2 INVENTORS JOHN R MATTSO/V A/VD R0) 0. MATTSO/V July 13, 1965 .-1.-R. MATTSON ETAL PROPULSION SYSTEM FOR SMALL BOATS Filed Jan. 31, 1963 5Sheets-Sheet 2 g I Z 1 I I 68 l I I I I I I 37 a i T- i h L I I 4 6 6848 I 4 I 1? l l 4 l h INVENTORS JOHN R MATTSO/V A/VD R0) 0. MATTSO/V y3, 1965 J. R. MATTSON ETAL 3,

PROPULSION SYSTEM FOR SMALL BOATS Filed Jan. 31, 1963 5 Sheets-Sheet 3INVENTORS JOHN R. MATT 80W AND R0) 0. MA 7' 7190/1! July 13, 1965 J. R.MATTSON ETAL 3,194,205 PROPULSION SYSTEM FOR SMALL BOATS Filed Jan. 31,1963 5 Sheets-Sheet 4 IIA VIIIIIMK mwgxx IIIIIIIIIIIlI/IIIJ '5':IIIIIIIIIIIIIIIIIII JOHN R MATTSO/V AND ROY D. MAT 7'50/V INVENTORS J.R. MATTSON E'fAL 3,194,205

July 13, 1965 PROPULSION SYSTEM FOR SMALL BOATS 5,Sheets-Sheet 5 59Filed Jan. 31, 1963 R0) 0. MA TTSO/V United States Patent PRDPULSEGNSYSTEM FOR SMALL BUATS John R. Mattson, 1491 Ripley Ave, and Roy D.Mattson, 415 Minnesota Ave, both of St. Paul, Minn. ..Filed Jan. 31,1963, Ser. No. 255,262 4 Claims. (@l. 115-12) This invention relates toa new and very useful hydraulic propulsion system for small open boats,especially shallow-draft boats such as canoes.

Propeller-type, deep-draft, high center of gravity, outboard motors whenattached to outrigger-type or sternlocated motor mounts on lightweight,shallow-draft water craft, such as canoes, create a hydrodynamicallyunstable condition owing to the associated rise in the center of gravityin the assembled combination. In addition, such combination displays amarked tendency to roll in the direction of applied torque to therotating propeller. Also, the overall draft of such combination isusually much greater than that of the vessel by itself and so thecombination does not permit boat operation in water only deep enough-tofloat the shallow-draft vessel without the motor-driven propeller.Furthermore, such combination displays a dangerous tendency to bank androll, even overturn the boat, when the boat is horizontally turned, asin steering, unless very gradual turns are made. For all of thsereasons, conventional propulsion systems for small boats such as speedboats and the like have generally not been adaptable to canoes, duckboats, and similar shallow-draft, portageable, light weight, commonlyoutrigger-equipped open boats.

In the present invention there is provided a novel, compact, hydraulicpropulsion system which utilizes a centrifugal pump and which, incombination with a lightweight, shallow-draft boat, requires only a fewmore inches of draft than does the boat by itself without the propulsionsystem.

It is an object of this invention to provide a compact, lightweight,hydraulic propulsion system for small open boats utilizing a centrifugalpump.

Another object of this invention to provide a hydraulic propulsionsystem which is adapted to have a center of gravity when in combinationwith a boat that is not above the normal water line of the boat as wellas. being not above the center of gravityof the boat itself, thuseffectively, actually increasing the overall stability of thecombination of boat plus propulsion system.

Another object of this invention is to provide a hydraulic propulsionsystem for small, lightweight, shallow-draft boats which eliminates thetendency of such boats to roll when equipped with conventional, highcenter of gravity propeller-driven propulsion systems. i

i It is another object of this invention to provide a propulsion systemfor boats which enables one to steer a boat equipped with this systemwithout the aid of a rudder, tiller or similar device.

It is another object of this invention to provide a hydraulic propulsionsystem for boats which allows boats equipped with this system excellentmaneuverability characteristics in all horizontal directions.

It is another object of this invention to provide a hydraulic propulsionsystem for small open boats which permits boats so equipped with thissystem to navigate in water too shallow for the same boats equipped withconventional propeller-type outboard or inboard propulsion means.

It is another object of this invention to provide an inboard hydraulicpropulsion system utilizing a centrifugal pump in which the power sourcemay be moved from the system while leaving the centrifugal pump andassociated mechanism without affecting adversely the capacity of the3,l94,25 Patented July 13, 1965 vessel to function and operate as anunpowered watercraft.

It is another object of this invention to provide a hydraulic propulsionsystem in which a centrifugal pump is driven by an internal combustionengine and in which, when the system is mounted inboard, exhaust fromthe internal combustion engine is vented into water beneath the boat andnot into the atmosphere within and about the boat.

It is a further object of this invention to provide a hydraulic systemwhich can be mounted inboard within a boat and which system can berotated from within the vessel so as to provide means for steering andmaneuvering the boat and at the same time allow exhaust gases from aninternal combustion engine used at the power source for the system to beexpelled into the water below the waterline of the vessel.

It is a further object of this invention to provide in a ing ofmechanical water seals utilized in therotatable power source andassociated mountings and propulsion means.

The. above, and still further highly important objects and advantages ofour invention will become apparent from the following detailedspecification, appended claims, and attached drawings.

Referring to the drawings, which illustrate the invention, and in whichlike reference characters indicate like parts throughout the severalviews:

FIG. 1 is a perspective view of an embodiment of a hydraulic propulsionsystem of the invention;

FIG. 2 is a horizontal section taken along the line 2-2 of FIG. 1; t

FIG. 3 is a view in perspective showing the casting mounting the powerhead, the impeller housing and the supporting column structure thereofof the embodiment of FIG. 1, some parts broken away and some parts shownin section;

FIG. 4 is a view in perspective of the casting mounting the power headand the exhaust manifold assembly associated therewith, as seen fromleft to right of FIG. 3, some parts broken away and some parts shown insection;

FIG. 5 is an exploded view in axial section of the impeller shaft andmeans for coupling said shaft to the power head of the embodiment ofFIG. 1;

FIG. 6 is a bottom plan view of the embodiment of FIG. 1;

FIG. 7 is a vertical sectional view taken along the line 7-7 of FIG. 1,some portions thereof broken away;

FIG. 8 is an enlarged fragmentary view in perspective of a portion of amodified form of the embodiment shown in FIG. 3, some parts thereofbroken away and some parts being shown in section; and

FIG. 9 is a fragmentary view in perspective similar to that shown inFIG. 8 showing a still further modified form of the embodiment shown inFIG. 3, some parts broken away and some parts shown in section.

Turning to the drawings, there is seen in FIG. 1 a hydraulic propulsionsystem of the invention herein designated in its entirety by the numeral20. The system comprises a power head 21 and a centrifugal pump 22. Whenthe impeller 19 in centrifugal pump 22 is rotated by the power head 21,water is ejected from ports 24 of pump 22.

The entire propulsion system 2% is, in effect, supported the impellerblade of the boat bottom and the sleeve 27.

upon a cylindrically shaped column 26 which, as will be explained, isactually composed of a plurality of separate elements. Journalling theexterior of this column 26 is a sleeve 27 which is flanged at its lowerend. This flange 31 on sleeve 27 rests on the bottom portion 25 of boat29 whenthe column 26 is'positioned in a normally vertical axis with thecolumn 2i; extending downwardly through the bottom 25 of boat 29 throughthe latters keel region. The flange 31 contains a plurality ofcircumferentially spaced holes whose respective axes are parellel tothat of shaft 23 and which are designed to receive mounting bolts andnuts 32 which extend through the bottom 28 of boat 29 and serve tosecurely mount the sleeve 27 against the boat bottom 25 Conveniently, agasket 33 is positioned between the flange 31 and the boat bottom 28 soas to make a water-tight seal between Another gasket member ispositioned in an appropriately formed groove on the inner wall of sleeve27 so as to keep the sleeve 27 in water-tight engagement with the column26.

In the region of the sleeve 27 the column 26 is actually formed by twoconcentrically arranged members, to ,wit, the pedestal portion 35 of themotor mounting block 37 and the anchoring post 33 of centrifugal pump22. Pedestal 36 is generally cylindrically shaped as is post 35 exceptthat a ridge 3% is formed as a longitudinally extending projection onthe outside wall of post 38. Ridge 35 is in general sliding engagementwith the inside wall of pedestal as and is so oriented as to be facingforward as respects the direction of movement through water in theassembled hydraulic propulsion system 20. A radially outwardly extendingcollar 48 is integrally formed in the top region of post 38 so as totelescopically engage the inside walls of pedestal 36. In anappropriately formed slot in pedestal 36 is positioned a gasket 47 whichserves to keep the collar 48 in water-tight engagement with the adjacentinner wall of pedestal 36. There is, thus, a void space or passagewayformed in column 26 between the inside wall of pedestal 35 and theoutside wall of post 53. Pedestal 36 and anchoring post 35 are gangedtogether for common axial rotational movements within sleeve 27 as bymeans of a set screw 39 mounted in the forward wall of pedestal 36 andextending therethrough into an aligned recess in the forward edge ofridge 3% of post 38. An exit port '45 is formed in the bottom of column26 below the bottom 28 of boat 29 extending in a rearward direction.Exit port is formed by slotting the rear wall of pedestal 36 and post38, as in the manner shown, for example, in FIG. 3.

A radially inwardly projecting shoulder is formed on the inside walls ofpost 38 near its bottom or base region and it is in the axiallyextending cylindrical region of this shoulder 41 that the lower portion25 of shaft 23 is journalled as by means of a pair of bearings 42positioned one at each end of the shoulder 41. A rubberized seal 43 atthe inside bottom region of the post 38 makes a Water-tight seal betweenshaft 23 and the inside wall of post 33.

, Conveniently, the pedestal 36 is integrally formed with the block 37as, for example, by casting aluminum metal. Conveniently formed withinblock 37 is a depending lobe Within lobe 46 are conveniently formed apair of passageways 51 and 52 which are vertically stacked with respectto one another, as respects pedestal 35. The passageway 52 communicateswith a channel 49 which interconnects passageway 52 with passageway 45.

Passageway 51 receives exhaust gases directly from the cylinder head ofthe power head, here an internal combustion engine 21. These gases areconducted from passageway 51 to passageway 52 by means of an exhaustmanifold pipe 53. The height of the pipe 53 in relation to the deck ortop of block 37 is determined by the height of water on the outside ofthe boat 29 in which the hydraulic propulsion system it of the inventionis to be used. The pipe 53 height should always be chosen so as to beabove the high-water level 65 on the side of the boat 29. Therelationship is illustrated in FIG. 4, where the water level 61 outsidethe boat limits the water level 62 inside pipe 53 when the system 20 ina boat 29 is not operating and the boat is at rest in the water. Thearrows in FIG. 4 indicate direction of exhaust gas flow when the system2% is in operation. There is thus pro vided a continuous passage fromthe cylinder head of internal combustion engine 21 to exit port 45, asfollows. pass through pipe 53 and into passageway 52. From passageway 52the gases enter channel 49 and pass into passageway 46 and thence outthrough exit port 45 into the water beneath the boat 25. It will beobserved that by having the height of pipe 53 so chosen as to always beabove the high-water mark or line, no water can enter into the cylinderhead region of the internal combustion engine 21. Thus, when the boat isidle in the water, water will enter exhaust port 45 and rise, perhaps,even high enough to fill passageway 52, but will not rise high enough topass through pipe 53 and down into the cylinder head region of internalcombustion engine 21.

The crankshaft 55 of internal combustion engine 21 is connected to theupper portion 44 of shaft 23 so that when the internal combustion engine21 is in position atop block 37, the lower portion of shaft 55 and theupper portion 44 of shaft 23 unite to form a continuous drive shaft.While any conventional method of uniting the two shaft portions 23 and55 can be employed, one which is useful here is to form a slot 56diametrically across the upper end of upper portion 44 and then to forma cup-shaped adapter element 57 on the lower end of threade shank whichscrews into a bore in the lower end of crankshaft 55. This cup-shapedadapter element 57 has diametrically extending therethrough a shear pin53, the diameter of such shear pin 58 being so chosen as to permit theshear pin 58 to lie in slot 56 when crankshaft 55 is engaged with shaft23. The shear strength of the shear pin 58 is so chosen that shouldtheimpeller 19 become jammed in any way during operation of thepropulsion system 20, the shear pin 58 will give way or rupture, therebyavoiding damage to the centrifugal pump 22.

Conveniently, block 3'7 is provided with a bolt hole or holes 59 forfastening the internal combustion engine 21 thereto. As engine 21 isconventional, it is not described in detail herein.

The centrifugal pump 22 is composed of a head plate 35 and a casing 65.Casing is fastened to the head plate 35 conveniently by means offlathead machine screws 54 arranged in spaced intervals around theperimeter of the head plate 35. The casing 65 has an input port 66axially positioned beneath the shaft 23 and below the impeller 19. Asthe impeller 19 rotates within casing 55 in the area between casing 65and head plate 35, water is drawn in through port 66 and forciblyejected through ports 2 positioned across the rear of casing 65 beneaththe head plate 35. Taken together, the combination of the impeller 19and the head plate 35 and casing 65 comprise what is conveniently termeda centrifugal pump, and those skilled in the art will appreciate thatany conventional design or arrangement of parts that functions for thepurpose intended is suitable for use in this invention.

It is desirable to cool exhaust gases from internal combustion engine 21so as to cause the manifold or crossover pipe 53 to be cool in operationand also so as to avoid any heating or overheating of the column 26 andassociated bearings, gaskets, etc. For this purpose water is injectedinto the crossover pipe 53 in its apex region through a delivery tube68. Delivery tube 68, then, conveniently enters crossover pipe 53through the apex region in the latter. Water is supplied to tube 68 fromthe body After entering the passageway 51, exhaust gases snoseos ofwater in which the hydraulic propulsion system 2t! is operating asfollows. Near the prow end of head plate 3'5 is formed a small port 69.This port 69 enters a channel '71 which is formed in the head plate 35and it is integrally connected to upstanding anchoring post 38 as bysuitable casting and drilling operations. Conveniently, if the channel71 is formed by drilling, each end thereof is stoppered by means of aplug 72. Near the uppermost end of the channel '71 a short exit channel73 is provided which extends laterally from the channel 73. through theside of pedestal 36. Channel 7.3 is joined with tube 68 by means of asuitable elbow fitting .7 3. Now, when the impeller 1 .9 is rotating,sufficient hydraulic pressure is developed in the prow region to forcewater in the chamber defined by head plate 35 and casing 65 upwardlyinto port 69 and through channels 71 and '73 and so through the tube 68into the crossover pipe 53. Thus, when the impeller 19 is rotating,water is injected into the crossover pipe 53. It will be appreciatedthat the faster the impeller 19 turns the more water is pumped into thecrossover pipe 53 which is a desirable condition for, in general, thehigher the r.p.m., the greater the temperature and volume of exhaustgases passing through crossover pipe 53 from internal combustion engine21. Therefore, at such times, a higher volume of water is needed forcooling purposes than when the impeller 19 is turning at engine idlingspeeds.

In FIGS. 8 and 9 are shown modified forms of that shown in FIGS. 1-7. Itshould be noted that the alternative embodiments of our invention shownin FIGS. 89 and hereinafter described corresponds in all respects notspecifically hereinafter mentioned to the above described embodiment ofour invention shown in FIGS. 1-7, and the parts or elements of saidalternative embodiment which correspond to like parts or elements inFIGS. 17 are denoted by the use of the same reference characters withprime marks added thereto. In the embodiment of FIG. 8, a modified formof cooling is used for the exhaust gases. Instead of conducting thewater pumped up into channel 71 into a pipe, the Water is led aroundthrough an annular groove 18 from ridge 3% to the mouth of channel 49.Exhaust gases porting through channel 49 into passageway 49 are cooledby the water by a splash action set up by the exhaust gas stream.

In FIG. 9 is shown another modification of the inven' tion which differsfrom that shown in FIGS. l-7 in two respects, to wit, in water coolingand in impeller shaft construction. In this embodiment, water entersthrough a port 76 on the leading edge of column 26. In this embodimentthe faster the boat is propelled through the water the more water enterschannel 76. Then when the water enters into the region 40' motion of theimpeller shaft 77 serves to splash the water around within the region40' and produce the desired cooling action so that the post 38 and thepedestal 36' do not become overheated. Also note in this embodiment thatthe shaft 77 consists of a single bar threaded at each end and is heldto axial alignment within post 38 by the connection with the internalcombustion engine on top of the block 37'. No other hearing or guidemeans need be employed since the shaft itself in this embodiment is maderigid enough to insure that the impeller 19' will rotate as desiredduring operation within the space defined between head plate 35 andcasing 65. In this embodiment only the single O-ring 7b is used inaddition to 34 and this seal 73 is fitted into the upper inside ofpedestal 36. O-ring sea 78 is the only means provided in this embodimentfor keeping water out of the boat. Thu-s, here the power head (notshown) cannot be removed while the boat is in the water as is the casewith the embodiment shown in FIGS. 17 and that shown in FIG. 8. Observethat the impeller shaft 77 threads directly into the engine crankshaftand that there is no seal at the bottom inside of the post 38 betweenthe shaft '77 and the inside wall of the post 33. Water entering throughthe channel 76 leaves the space 4d through the exit port 45'.

Our invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the above objects, and while wehave shown and described a preferred embodiment, we wish it to bespecificially understood that the same is capable of modificationwithout departure from the spirit and scope of the appended claims.

What is claimed is:

1. A hydraulic propulsion system for small open boats 0 comprising:

(a) a cylindrically shaped mounting column,

(b) means adapted to be secured to the interior bottom portion of .aboat at the keel region of the boat and journalling said columnfol-steering rotation on a normally vertical axis with said columnextending downwardly through the bottom below the keel of said boat,

(0) a drive shaft axially extending through, and journalled for rotarymovement in said column,

(d) an impeller mounted on the bottom end of said shaft,

to) a housing for said impeller having water intake and exhaust portmeans and being adapted to convert horizontal rotational movements ofsaid impeller into laterally exerted hydraulic thrust,

(f) said housing being rigidly secured to the bottom of aid column forcommon rotation therewith,

g) on internal combustion engine mounted on the top of said column belowthe high water line on the eX- terior of said boat,

(h) exhaust passage means communicating with said internal combustionengine and .a port defined by said column below the bottom of said boat,

(i) and means positively preventing pass-age of water through saidexhaust passage means to said engine when said engine is in disuse orremoved and when said boat is resting in said water under said highwater line condition.

2. The structure defined in claim I in which said last mentioned meanscomprises an inverted U-shaped pipe element, the uppermost portion ofwhich projects above said high water line.

3. The structure defined in claim 2 in further combination with meansfor introducing water under pressure into said pipe element whereby tocool same.

t. The structure defined in claim 3 in which said last mentioned meanscomprises a conduit means communicat- 'ig with said impeller housingintermediate the water intake and exhaust port means thereof and theuppermost portion of said Ushaped pipe.

References (Iited by the Examiner UNITED STATES PATENTS 799,013 9/ 05Moflitt 60-30 803,177 10/05 Lake 60- 29 X 1,484,881 2/24 Gill 60-35.551,816,371 7/31 Hefti 34 2,935,039 5/60 Thompson 1l5.5 3,035,409 5/62'Pifer 60-35.55 X 3,098,464 7/63 Holland 115-16 FOREIGN PATENTS 654,69112/37 Germany. 877,982 9/ 61 Great Britain.

FERGUS S. MIDDLETON, Primary Examiner.

1. HYDRAULIC PROPULSION SYSTEM FOR SMALL OPEN BOATS COMPRISING: (A) ACYLINDRICALLY SHAPED MOUNTING COLUMN, (B) MEANS ADAPTED TO BE SECURED TOTHE INTERIOR BOTTOM PORTION OF A BOAT AT THE KEEL REGION OF THE BOAT ANDJOURNALLING SAID COLUMN FOR STEERING ROTATION ON A NORMALLY VERTICALAXIS WITH SAID COLUMN EXTENDING DOWNWARDLY THROUGH THE BOTTOM BELOW THEKEEL OF SAID BOAT, (C) A DRIVE SHAFT AXIALLY EXTENDING THROUGH, ANDJOURNALLED FOR ROTARY MOVEMENT IN SAID COLUMN, (D) AN IMPELLER MOUNTEDON THE BOTTOM END OF SAID SHAFT, (E) A HOUSING FOR SAID IMPELLER HAVINGWATER INTAKE AND EXHAUST PORT MEANS AND BEING ADAPTED TO CONVERTHORIZONTAL ROTATIONAL MOVEMENTS OF SAID IMPELLER INTO LATERALLY EXERTEDHYDRAULIC THRUST, (F) SAID HOUSING BEING RIGIDLY SECURE TO THE BOTTOM OFSAID COLUMN FOR COMMON ROTATION THEREWITH, (G) AN INTERNAL COMBUSTIONENGINE MOUNTED ON THE TOP OF SAID COLUMN BELOW THE HIGH WATER LINE ONTHE EXTERIOR OF SAID BOAT, (H) EXHAUST PASSAGE MEANS COMMUNICATING WITHSAID INTERNAL COMBUSTION ENGINE AND A PORT DEFINED BY SAID COLUMN BELOWTHE BOTTOM OF SAID BOAT, (I) AND MEANS POSITIVELY PREVENTING PASSAGE OFWATER THROUGH SAID EXHAUST PASSAGE MEANS TO SAID ENGINE WHEN SAID ENGINEIS IN DISUSE OR REMOVED AND WHEN SAID BOAT IS RESTING IN SAID WATERUNDER SAID HIGH WATER LINE CONDITION.